Effect of Resonant and Nonresonant Magnetic Braking on Error Field Tolerance in High Beta Plasmas


 Tracey Wilcox
 1 years ago
 Views:
Transcription
1 1 EX/53Ra Effect of Resonant and Nonresonant Magnetic Braking on Error Field Tolerance in High Beta Plasmas H. Reimerdes 1), A.M. Garofalo 2), E.J. Strait 2), R.J. Buttery 3), M.S. Chu 2), Y. In 4), G.L. Jackson 2), R.J. La Haye 2), M.J. Lanctot 1), Y.Q. Liu 3), J.K. Park 5), M. Okabayashi 5), M.J. Schaffer 2), and W.M. Solomon 5) 1) Columbia University, New York, New York 10027, USA 2) General Atomics, P.O. Box 85608, San Diego, California , USA 3) EURATOM/UKAEA Fusion Association, Culham Science Centre, OX14 3DB, UK 4) FARTECH, Inc., San Diego, California 92121, USA 5) Princeton Plasma Physics Laboratory, Princeton, New Jersey , USA contact of main author: Abstract. Tokamak mas become less tolerant to externally applied nonaxisymmetric magnetic error fields as beta increases, due to a resonant interaction of the nonaxisymmetric field with a stable n = 1 kink mode. Similar to observations in low beta mas, the limit to tolerable n = 1 magnetic field errors in neutral beam injection heated Hmode mas is seen as a bifurcation in the torque balance, which is followed by error field driven locked modes and severe confinement degradation or a disruption. The error field tolerance is, therefore, largely determined by the braking torque resulting from the nonaxisymmetric magnetic field. DIIID experiments distinguish between a resonantlike torque, which decreases with increasing rotation, and a nonresonantlike torque, which increases with increasing rotation. While only resonant braking leads to a rotation collapse, modeling shows that nonresonant components can lower the tolerance to resonant components. The strong reduction of the error field tolerance with increasing beta, which has already been observed in early high beta experiments in DIIID [R.J. La Haye, et al., Nucl. Fusion 32, 2119 (1992)], is linked to an increasing resonant field amplification resulting from a stable kink mode [A.H. Boozer, Phys. Rev. Lett. 86, 5059 (2001)]. The amplification of externally applied n = 1 fields is measured with magnetic pickup coils and seen to increase with beta, with the increase accelerating above the no wall ideal MHD stability limit, where the ideal MHD stable kink mode converts to a kinetically stabilized resistive wall mode. The beta dependence was not previously appreciated, and was not included in the empirical scaling of the error field tolerance reported in the 1999 IPB [ITER Physics Basis, Nucl. Fusion 39, 2137 (1999)] leading to overly optimistic predictions for low torque, high beta scenarios. However, the measurable increase of the ma response with beta can be exploited for dynamic correction (i.e. with slow magnetic feedback) of the amplified error field. 1. Introduction Tokamak mas are very sensitive to nonaxisymmetric perturbations of the externally applied magnetic error field. Small perturbations in the order of δb ext /B T 10 4, where B T is the toroidal magnetic field, can lead to locked modes in Ohmically heated, low density mas and to rotation and pressure collapses in neutral beam injection (NBI) heated Hmode discharges. While the error field tolerance is usually described by empirical scaling laws (e.g., [1]), which are based on Ohmic locked mode experiments (e.g., [2]) and mainly depend on the electron density n e, early high β experiments in DIIID, with β 2µ 0 p / B T 2 being the normalized volume averaged ma pressure, already showed a strong reduction of the error field tolerance with β [3]. The n = 1 error field threshold in high β discharges was initially interpreted as a stability threshold with magnetic braking leading to a loss of rotational stabilization and, consequently, an unstable resistive wall mode (RWM). However, it has recently been pointed out that, similar to the low β locked mode experiments, the n = 1 error field tolerance of high β mas is caused by a bifurcation in the torque balance [4]. The presented work investigates the role of magnetic braking in determining the error field tolerance of high β mas, draws the link to low β experiments and discusses the consequences for ITER.
2 2 EX/53Ra 2. Error Field Tolerance of High Beta Plasmas The error field tolerance is systematically studied in controlled magnetic braking experiments in weakly shaped, lowersingle null Hmode discharges (B T = 2.0 T, I P = 1.1 MA, q , q min 1.5), which have Advanced Tokamak relevant qprofiles but low ideal MHD β limits. The experiments take advantage of the flexible nonaxisymmetric control coil sets on DIIID. While a set of six external control coils (Ccoils) empirically corrects the intrinsic error field, two sets of six internal control coils each (Icoils) located above and below the outboard midplane apply a wellknown nonaxisymmetric perturbation. The phase difference Δφ I between the n = 1 field applied with the upper and the lower Icoil arrays can be varied to modify the poloidal spectrum of the externally applied field. The Icoil is usually configured with a phase difference Δφ I = 240 deg, where 1 ka of n = 1 current generates a resonant field at the q = 2 surface of approximately B ext G Torque Balance and Error Field Penetration In order to study the torque balance, the Icoil currents are programmed to generate a slowly rotating (10 Hz) n = 1 field whose amplitude increases on a time scale, which is slow compared to a typical angular momentum confinement time τ L of 50 ms, Fig. 1(a,b). As the n = 1 field is ramped up, the toroidal ma rotation Ω, which is measured with charge exchange recombination spectroscopy using CVI emission, decreases, Fig. 1(c), and the n = 1 ma response B p, measured with a toroidal array of poloidal magnetic field probes at the outboard midplane increases, Fig. 1(d), until the rotation collapses at t = 2910 ms. The collapse is followed by an error fielddriven locked mode, which can be seen on the electron temperature T e contours Fig. 1(e) as the externally applied field rotates the island past the electron cyclotron emission (ECE) diagnostic [5] and which leads to a severe degradation of the confinement. The characteristics of the FIG. 1. Increasing the amplitude of a slowly rotating n = 1 Icoil field (a,b) leads to a decrease of the rotation Ω (c) and an increase of the n = 1 ma response B p (d). The rotation collapse is followed by error field penetration seen on the electron temperature T e contours (e). error field limit in these high β Hmodes are similar to the observations in low density, locked mode experiments in Ohmic mas (e.g., [2]). It is understood that a sufficiently large ma rotation induces helical currents at rational surfaces q = m/n, which cancel the resonant harmonics of the externally applied field and suppress the formation of islands. The finite resistivity leads to dissipation and consequently a torque, which slows the ma rotation. The evolution of the ma rotation can be described by I dω dt = T in IΩ τ L,0 T MB, (1)
3 3 EX/53Ra where I is the moment of inertia, T in the sum of all accelerating torques and τ L,0 the momentum confinement time in the absence of nonaxisymmetric fields. When the magnetic braking torque T MB increases sufficiently fast with decreasing Ω, the torque balance can be lost and the rotation collapses [6]. If T MB is proportional to Ω 1 and the viscous transport described by a momentum confinement time, the torque balance Eq. (1) predicts this bifurcation to occur at a critical rotation Ω crit = T in τ L,0 /(2I). If T in is kept constant, this corresponds to half of the unperturbed rotation, Ω crit = Ω 0 /2. When the ma rotation is too low to induce the helical shielding currents, the error field penetrates and an island opens, consistent with the observations, Fig. 1. In DIIID the characteristic relation between Ω 0 and Ω crit has been observed in several ma scenarios and over a wide range of rotation values [4,7]. High β low rotation discharges are also particularly prone to the onset of m/n=2/1 neoclassical tearing modes (NTMs) [8] caused by a decrease of their β N threshold with decreasing rotation in the direction of the ma current [9]. In addition to affecting the tearing stability through braking of the ma rotation, nonaxisymmetric fields are also thought to directly reduce the NTM β N threshold [10]. These modes, which are typically born rotating but quickly lock, are occasionally observed during the Icoil ramps and limit operation towards higher β N and lower Ω Torque Balance and Dependence of Error Field Tolerance on NBI Torque/Rotation Since the error field tolerance is determined by the loss of torque balance, it should improve with increasing torque input to the ma. Assuming a viscoresistive resonant magnetic braking torque, T MB = K R δ B 2 R Ω 1 [6], the torque balance according to Eq. (1) is lost when the magnetic perturbation exceeds a critical amplitude, τ δb R,crit = T L,0 in 4 I K R 1/ 2. (2) According to Eq. (2), the error field tolerance should increase linearly with the NBI torque T NBI, which is usually the dominant torque input. FIG. 2. The tolerable n = 1 Icoil field ( I crit ) increases with increasing NBI torque T NBI. A linear fit yields a torque offset of 7.0 Nm. An alternative fit is discussed in Section 3.3. The dependence of the n = 1 error field tolerance on T NBI is measured using the DIIID capability to vary T NBI independently of the NBI heating power P NBI. The externally applied n = 1 field is increased in discharges, which only differ in the value of T NBI. In these discharges feedback control of P NBI keeps β N = 2.0 constant. Varying T NBI by a factor of 3 leads to an increase of the tolerable Icoil current I crit, and hence the tolerable externally applied field, by 50%, Fig. 2. Comparing a linear fit of I crit versus T NBI with Eq. (2) yields a torque offset T 0 = T in T NBI of 7Nm. While such an offset in the direction of the ma current could be due to the intrinsic rotation of the ma, a value of 7Nm is several times larger than expected [11]. Alternatively, the increase of error field tolerance with increasing T NBI could be reduced due to a deviation from the Ω 1 dependence of T MB as discussed in Section Dependence of Error Field Tolerance on Beta and Role of Plasma Response The dependence of the n = 1 error field tolerance on β N is measured in similar discharges with β N ranging from 1.5 to 2.3. A comparison of two discharges with T NBI = 1.8 Nm shows that a 33% increase in β N from 1.5 and 2.0, Fig. 3(a), halves the tolerable externally applied field ( I crit ), Fig. 3(b). At higher β N a smaller externally applied field leads to a similar rotation decay and the rotation collapse occurs at approximately the same rotation, Fig. 3(c).
4 4 EX/53Ra At higher β N the n = 1 ma response B p to the externally applied field is, however, also larger resulting in the same B p at the time of the rotation collapse, Fig. 3(d). The continuation of the β N scan at a higher value of T NBI 4.2 Nm shows that the decrease of the error field tolerance with β N even accelerates at higher values of β N, Fig. 3(e). Again the ma response to the externally applied field increases accordingly so that B p at the collapse remains constant, Fig. 3(f). The observed β N dependence of the tolerance to externally applied n = 1 fields can, therefore, be explained by a magnetic braking torque that dominantly depends on the ma response rather than the externally applied (vacuum) perturbation. The tolerable ma perturbation B p,crit increases with T NBI, consistent with the results of the torque scan in Section 2.2. FIG. 3. At constant T NBI 1.8 Nm the discharge with the higher β N (a) displays a lower tolerance against n = 1 field asymmetries applied with the Icoil (b) than the discharge with a lower β N. The collapse of the rotation Ω (c) occurs at the same ma response B p (d). A β N scan at T NBI 4.2 Nm (red) (e) shows that the decrease of the tolerance to externally applied n = 1 fields ( I crit ) with β N accelerates further when β N exceeds the nowall limit. For each value of T NBI the ma response at the collapse B p,crit (f) is independent of β N Dependence of the Error Field Tolerance on the Poloidal Spectrum The dependence of the error field on the poloidal spectrum of the externally applied field is investigated by probing similar mas (β N 2.2, T NBI = 4.5 Nm) with Icoil fields that differ from the standard phase difference of Δφ I = 240 deg, Fig. 4(a). Reducing Δφ I to 180 deg allows approximately for a doubling of the Icoil current and, hence, the externally applied field before the rotation collapses, Fig. 4(a,b). In the case of Δφ I = 120 deg the currents in the Icoil can even be ramped up to the powersupply limited maximum current of 4.5 ka while causing only modest braking. Again the braking is related to the ma response, with the rotation collapse occurring at B p,crit 10 G, Fig. 4(c). The coupling of a field resulting from Δφ I = 240 deg to the ma is approximately six times more effective than the coupling to a field resulting from Δφ I = 120 deg, Fig. 4(d). At the same time the resonant component of the externally applied field at the q=2 surface B ext 21 remains the same Understanding of the Plasma Response The role of the ma response to enhance the torque of uncorrected error fields in wallstabilized mas is well known [12] and has been attributed to resonant amplification of the
5 5 EX/53Ra FIG. 4. Discharges with constant β N = 2.2 are perturbed with Icoil fields with different phase differences Δφ I (a). While the discharges with Δφ I = 180 deg and 240 deg experience a rotation collapse (b), the current for Δφ I = 120 deg can be increased to 4.5 ka while causing only modest braking. The critical current for Δφ I = 180 deg is higher than for 240 deg, but the corresponding ma response remains the same (c). While the Δφ I dependence of the coupling of the externally applied field to the ma B p / I I coil (diamonds) does not correlate with B ext 21 (q=2) (squares), it is well described by modeling with the MARSF code (d). weakly damped, but stable n = 1 RWM [13]. Once β N exceeds the nowall limit, small externally applied n = 1 fields can drive the stable RWM to a large amplitude. The interaction of nonaxisymmetric fields with the ma can be modeled with the MARSF code [14]. It is thought that the stabilization of the RWM is a result of kinetic effects [15], but the present implementation of semikinetic stabilization in MARSF [16] still falls short of a quantitative description of the experimental observations [7]. While a quantitative prediction of the damping rate and, hence amplification is not expected, the code can describe the coupling of external fields to the kink mode. The n = 1 ma response at the location of the B p measurements is calculated for Icoil fields with various phase differences Δφ I, Fig. 4. The equilibrium of discharge at t = 1750 ms is ideal MHD unstable and soundwave damping [17] is added to stabilize the ma. Varying only Δφ I yields the best coupling for Δφ I = 300 deg. The calculation correctly describes the observed large increase of the coupling when Δφ I is increased from 120 to 240 deg, Fig. 4(d). It is important to note that the ma response is not caused by the components of the externally applied field that are resonant with field lines inside the ma, but by the component with a smaller pitch angle that is resonant with the kink mode. The ma response below the nowall limit has similar characteristics, showing the same perturbed field pattern at the wall and no evidence for island formation provided the ma is rotating. It is, therefore, also likely linked to the (ideal MHD stable) n = 1 kink mode. Error field correction experiments on DIIID and NSTX have revealed the importance of the ideal MHD ma response even in Ohmically heated low β mas [18]. The present experiments confirm the role of the ma response at intermediate values of β N, bridging the gap between locked mode experiments in Ohmic discharges and errorfield correction in wallstabilized high β N mas. Despite a value of β N = 1.5, which is significantly below the nowall limit, the ma response in discharge , Fig. 3(a d), reaches values of up to B p (n=1) 7 G prior to the rotation collapse. Modeling of the perturbed field at the rotation collapse using the Ideal Perturbed Equilibrium Code (IPEC) [19] results in a total resonant field at the q = 2 surface of B G (using PEST coordinates). With an average electron density of n e = m 3 this value for B 21 lines up remarkably well with an extrapolation based on the usual density dependence of the error field tolerance in Ohmic mas (e.g., [3]) and the corresponding IPEC calculation for DIIID [18], which results in B G. The excess of approximately 15% in over the Ohmic scaling can easily be
6 6 EX/53Ra attributed to the modest NBI torque of 1.8 Nm, which should increase the error field tolerance, Section 2.2. In high β N discharges experimental observations [20] as well as modeling with the MARSF code [21] indicate that the response of a stable ma to externally applied nonaxisymmetric fields is well described by a single least stable mode. A similar conclusion is reached from the IPEC analysis of low beta mas [18]. Consequently, correction coils even with a poorly matched magnetic field pattern should be effective in suppressing the ma response and avoiding a rotation collapse. 3. Magnetic Braking Since the error field limit manifests itself by a loss of torque balance, the error field tolerance is determined by the torque that the nonaxisymmetric perturbation exerts on the ma Rotation Evolution and Calculation of the Magnetic Braking Torque In experiments with slowly increasing Icoil currents, the toroidal ma rotation decreases across the entire profile, Fig. 5(a). In addition to a continuous rotation decrease, the rotation measurements taken at a fixed location also oscillate with the externally imposed rotation frequency f ext = 10 Hz. This oscillation is caused by a superposition of the externally applied rotating n = 1 field with a residual (imperfectly corrected) n = 1 intrinsic error field as well as convective transport with the kinktype displacement of the ma response. The rotation profile during the slow braking phase does not show any evidence of a localized braking torque, Fig. 5(b). However, diffusive transport, the finite spatial resolution of the rotation measurements and the uncertainty of the measurements limit the detectability of a localized torque. Once the externally applied field exceeds the critical value (at t 2140 ms) the rotation collapse starts in the outer half of the ma but quickly (typically in the order of 10 ms) propagates inwards, Fig. 5(a). FIG. 5. Ramping up the Icoil current leads to a decay of the rotation across the entire profile (a). The rotation collapse starts in the outer half of the ma but quickly affects the entire profile. Rotation measurements prior to the collapse (b) do not reveal any localized braking torque Frequency Dependence of the Torque The magnetic braking torque T MB is obtained from the measured global rotation evolution, T MB = T NBI L dl τ L,0 dt. (3) The profiles for the transport calculation are averaged over the externally imposed oscillation period of T ext = 100 ms in order to suppress the nonaxisymmetric effects on the
7 7 EX/53Ra measurements discussed above, which are not part of the transport calculation. Since most magnetic torque models rely on a δj δb torque, where δj is induced through δb, it is tenable to assume that the magnetic torque has a δb 2 dependence. Normalizing T MB with δb 2 then reveals the Ω dependence, which is shown for Ω at the q = 2 surface for several discharges in Fig. 6. While the discharge with the lowest rotation shows a torque that increases with decreasing Ω the high rotation discharges show a torque that decreases with decreasing Ω. The lowest torque is encountered when the rotation evaluated at the q = 2 surface is approximately 30 krad/s. FIG. 6. The normalized magnetic braking torque T MB /δb 2 has a minimum at a rotation at q = 2 of Ω(q=2) 30 krad/s Comparison of Resonant and Nonresonant Braking While a magnetic torque that depends on Ω 1 is usually associated with resonant braking and a torque that is proportional to Ω with nonresonant braking [22], the actual Ωdependencies depend on the parameter regime (e.g., [6]). In this work a torque T R = K R δ B 2 R Ω 1 is referred to as resonantlike and T NR = K NR δ B 2 NR Ω as nonresonantlike torque. Adding a nonresonantlike to the typical resonantlike torque in the angular momentum evolution, I dω dt = T in IΩ K NR δb 2 NR Ω K R δb 2 R Ω 1 (4) τ L,0 results in a decrease of the rotation at the collapse from the characteristic Ω crit = Ω 0 /2 of the resonant braking model (assuming that all other torques stay constant and that the viscous momentum transport is described by a momentum confinement time) to τ L* Ω crit = 1 Ω 0. (5) 2 τ L,0 The effective momentum confinement time τ L* = (τ 1 L,0 + I 1 K NR δb 2 NR ) 1 in Eq. (5) accounts for the confinement reduction caused by nonresonantlike magnetic braking. In experiments where T NBI is kept constant the critical rotation Ω crit indeed indicates a deviation from the simple scaling with Ω crit at the highest initial rotation values Ω 0 falling below Ω 0 /2, Fig. 7. Moreover, Ω crit never exceeds 30 krad/s, which is close to the minimum of the torque, Fig. 6. While a nonresonant torque cannot cause a bifurcation in the torque balance, it reduces the tolerable resonant field, which in the limit of large δb NR becomes, 1 δb R,crit = T in δb NR ( ) 1/ 2. (6) 4K R K NR FIG. 7. The critical rotation Ω crit (q=2) never exceeds 30 krad/s. Discharges with an unperturbed rotation Ω 0 (q=2) > 60 krad/s fall below the Ω crit = Ω 0 /2 scaling. Since both, δb R and δb NR are proportional to I Icoil, the linear dependence of I crit on T in motivated by Eq. (2) is reduced to I crit T in 0.5. A fit of the measured values of I crit to (T 0 + T NBI ) 0.5 results in an offset T 0 = 1.7 Nm, Fig. 2, which is more compatible with an intrinsic rotation.
8 8 EX/53Ra 4. Conclusion and Summary The limit to tolerable externally applied n = 1 error fields in tokamak mas is caused by a bifurcation in the torque balance, which is followed by an error fielddriven locked mode. The error field tolerance can be improved by increasing the torque input, e.g., with tangential NBI. The error field tolerance decreases with increasing β N. This important β N dependence was not previously appreciated, and was not included in the empirical scaling of the error field tolerance reported in the 1999 ITER Physics Basis [1]. The β N dependence is explained by the dominant role of the ma response to the externally applied field in the braking. Varying the poloidal spectrum of the externally applied field shows that the ma response is caused by a resonant amplification of the stable n = 1 kink mode. The increase of the amplification with β N accelerates as the ideal MHD stable kink mode converts into a kinetically stabilized RWM above the nowall stability limit. This has three important consequences for the (re)evaluation of the error field tolerance in ITER: (1) Neglecting the β N dependence in empirical scaling can lead to overly optimistic predictions for low torque, high β N scenarios and, in particular, for advanced tokamak scenarios, which rely on operation in the wallstabilized regime. (2) The error field tolerance has to be specified for the component that couples best to the kink mode, which has a lower pitch angle than the n = 1 field that is resonant with rational surfaces inside the ma and currently used for empirical scaling laws. (3) Correction coils even with a poorly matched magnetic field pattern should be effective in suppressing the ma response and avoiding a rotation collapse. The measurable increase of the ma response with β N can then be exploited for dynamic correction of the field error using slow magnetic feedback. Acknowledgments The authors would like to thank Prof. A.H. Boozer and Drs. K.H. Burrell, A.J. Cole and S.A. Sabbagh for insightful discussions. This work was supported by the US Department of Energy under DEFG0289ER53297, DEFC0204ER54698 and DEAC0276CH References [1] ITER PHYSICS BASIS, Nucl. Fusion 39, 2137 (1999). [2] HENDER, T.C., et al., Nucl. Fusion 32, 2091 (1992). [3] La HAYE, R.J., HYATT, A.W. and SCOVILLE, J.T., Nucl. Fusion 32, 2119 (1992). [4] GAROFALO, A.M., et al., Nucl. Fusion 47, 1121 (2007). [5] GAROFALO, A.M., et al., Am. Phys. Soc (2007). [6] FITZPATRICK, R., Nucl. Fusion 33, 1049 (1993). [7] REIMERDES, H., et al., Plasma Phys. Control. Fusion 49, B349 (2007). [8] OKABAYASHI, M., et al., this conference, EX/P95. [9] BUTTERY, R.J., et al., Phys. Plasmas 15, (2007). [10] BUTTERY, R.J., et al., this conference, IT/P68. [11] SOLOMON, W.M., et al., this conference EX/34. [12] GAROFALO, A.M., et al., Phys. Plasmas 9, 1997 (2002). [13] BOOZER, A.H., Phys. Rev. Lett. 86, 5059 (2001). [14] LIU, Y.Q., et al., Phys. Plasmas 7, 3681 (2000). [15] HU, B., BETTI, R., Phys. Rev. Lett. 93, (2004). [16] BONDESON, A., CHU, M.S., Phys. Plasmas 3, 3013 (1996). [17] BONDESON, A., WARD, D.J., Phys. Rev. Lett. 72, 2709 (1994). [18] PARK, J.K., SCHAFFER, M.J., MENARD, J.M., BOOZER, A.H., Phys. Rev. Lett. 99, (2007). [19] PARK, J.K., BOOZER, A.H., GLASSER, A.H., Phys. Plasmas 14, (2007). [20] REIMERDES, H., et al., Phys. Rev. Lett. 93, (2004). [21] LIU, Y., et al., Phys. Plasmas 13, (2006). [22] SHAING, K.C., Phys. Plasmas 10, 1443 (2003).
GA A26247 EFFECT OF RESONANT AND NONRESONANT MAGNETIC BRAKING ON ERROR FIELD TOLERANCE IN HIGH BETA PLASMAS
GA A26247 EFFECT OF RESONANT AND NONRESONANT MAGNETIC BRAKING ON ERROR FIELD TOLERANCE IN HIGH BETA PLASMAS by H. REIMERDES, A.M. GAROFALO, E.J. STRAIT, R.J. BUTTERY, M.S. CHU, Y. In, G.L. JACKSON, R.J.
More informationResistive Wall Mode Control in DIIID
Resistive Wall Mode Control in DIIID by Andrea M. Garofalo 1 for G.L. Jackson 2, R.J. La Haye 2, M. Okabayashi 3, H. Reimerdes 1, E.J. Strait 2, R.J. Groebner 2, Y. In 4, M.J. Lanctot 1, G.A. Navratil
More informationDIII D. by M. Okabayashi. Presented at 20th IAEA Fusion Energy Conference Vilamoura, Portugal November 1st  6th, 2004.
Control of the Resistive Wall Mode with Internal Coils in the Tokamak (EX/31Ra) Active Measurement of Resistive Wall Mode Stability in Rotating High Beta Plasmas (EX/31Rb) by M. Okabayashi Presented
More informationRWM FEEDBACK STABILIZATION IN DIII D: EXPERIMENTTHEORY COMPARISONS AND IMPLICATIONS FOR ITER
GA A24759 RWM FEEDBACK STABILIZATION IN DIII D: EXPERIMENTTHEORY COMPARISONS AND IMPLICATIONS FOR ITER by A.M. GAROFALO, J. BIALEK, M.S. CHANCE, M.S. CHU, D.H. EDGELL, G.L. JACKSON, T.H. JENSEN, R.J.
More informationRESISTIVE WALL MODE STABILIZATION RESEARCH ON DIII D STATUS AND RECENT RESULTS
RESISTIVE WALL MODE STABILIZATION RESEARCH ON STATUS AND RECENT RESULTS by A.M. Garofalo1 in collaboration with J. Bialek,1 M.S. Chance,2 M.S. Chu,3 T.H. Jensen,3 L.C. Johnson,2 R.J. La Haye,3 G.A. Navratil,1
More informationA New Resistive Response to 3D Fields in Low Rotation Hmodes
in Low Rotation Hmodes by Richard Buttery 1 with Rob La Haye 1, Yueqiang Liu 2, Bob Pinsker 1, Jongkyu Park 3, Holger Reimerdes 4, Ted Strait 1, and the DIIID research team. 1 General Atomics, USA 2
More informationGA A26242 COMPREHENSIVE CONTROL OF RESISTIVE WALL MODES IN DIIID ADVANCED TOKAMAK PLASMAS
GA A26242 COMPREHENSIVE CONTROL OF RESISTIVE WALL MODES IN DIIID ADVANCED TOKAMAK PLASMAS by M. OKABAYASHI, I.N. BOGATU, T. BOLZONELLA, M.S. CHANCE, M.S. CHU, A.M. GAROFALO, R. HATCHER, Y. IN, G.L. JACKSON,
More informationGA A27444 PROBING RESISTIVE WALL MODE STABILITY USING OFFAXIS NBI
GA A27444 PROBING RESISTIVE WALL MODE STABILITY USING OFFAXIS NBI by J.M. HANSON, F. TURCO M.J. LANCTOT, J. BERKERY, I.T. CHAPMAN, R.J. LA HAYE, G.A. NAVRATIL, M. OKABAYASHI, H. REIMERDES, S.A. SABBAGH,
More informationResistive wall mode stabilization by slow plasma rotation in DIIID tokamak discharges with balanced neutral beam injection a
PHYSICS OF PLASMAS 14, 056101 2007 Resistive wall mode stabilization by slow plasma rotation in DIIID tokamak discharges with balanced neutral beam injection a E. J. Strait, b A. M. Garofalo, c G. L.
More informationRequirements for Active Resistive Wall Mode (RWM) Feedback Control
Requirements for Active Resistive Wall Mode (RWM) Feedback Control Yongkyoon In 1 In collaboration with M.S. Chu 2, G.L. Jackson 2, J.S. Kim 1, R.J. La Haye 2, Y.Q. Liu 3, L. Marrelli 4, M. Okabayashi
More informationGA A27910 THE SINGLEDOMINANT MODE PICTURE OF NONAXISYMMETRIC FIELD SENSITIVIITY AND ITS IMPLICATIONS FOR ITER GEOMETRIC TOLERANCES
GA A279 THE SINGLEDOMINANT MODE PICTURE OF NONAXISYMMETRIC FIELD SENSITIVIITY AND ITS IMPLICATIONS FOR ITER by C. PAZSOLDAN, K.H. BURRELL, R.J. BUTTERY, J.S. DEGRASSIE, N.M. FERRARO, A.M. GAROFALO,
More informationDynamical plasma response of resistive wall modes to changing external magnetic perturbations
Dynamical plasma response of resistive wall modes to changing external magnetic perturbations M. Shilov, C. Cates, R. James, A. Klein, O. KatsuroHopkins, Y. Liu, M. E. Mauel, D. A. Maurer, G. A. Navratil,
More informationDynamical plasma response of resistive wall modes to changing external magnetic perturbations a
PHYSICS OF PLASMAS VOLUME 11, NUMBER 5 MAY 2004 Dynamical plasma response of resistive wall modes to changing external magnetic perturbations a M. Shilov, b) C. Cates, R. James, A. Klein, O. KatsuroHopkins,
More informationGA A26887 ADVANCES TOWARD QHMODE VIABILITY FOR ELMFREE OPERATION IN ITER
GA A26887 ADVANCES TOWARD QHMODE VIABILITY FOR ELMFREE OPERATION IN ITER by A.M. GAROFALO, K.H. BURRELL, M.J. LANCTOT, H. REIMERDES, W.M. SOLOMON and L. SCHMITZ OCTOBER 2010 DISCLAIMER This report was
More informationEffect of an error field on the stability of the resistive wall mode
PHYSICS OF PLASMAS 14, 022505 2007 Effect of an error field on the stability of the resistive wall mode Richard Fitzpatrick Institute for Fusion Studies, Department of Physics, University of Texas at Austin,
More informationAnalysis and modelling of MHD instabilities in DIIID plasmas for the ITER mission
Analysis and modelling of MHD instabilities in DIIID plasmas for the ITER mission by F. Turco 1 with J.M. Hanson 1, A.D. Turnbull 2, G.A. Navratil 1, C. PazSoldan 2, F. Carpanese 3, C.C. Petty 2, T.C.
More informationResistive Wall Mode Stabilization and Plasma Rotation Damping Considerations for Maintaining High Beta Plasma Discharges in NSTX
1 EXS/55 Resistive Wall Mode Stabilization and Plasma Rotation Damping Considerations for Maintaining High Beta Plasma Discharges in NSTX S.A. Sabbagh 1), J.W. Berkery 1), J.M. Bialek 1), R.E. Bell ),
More informationResistive Wall Mode Observation and Control in ITERRelevant Plasmas
Resistive Wall Mode Observation and Control in ITERRelevant Plasmas J. P. Levesque April 12, 2011 1 Outline Basic Resistive Wall Mode (RWM) model RWM stability, neglecting kinetic effects Sufficient for
More informationFormation and Long Term Evolution of an Externally Driven Magnetic Island in Rotating Plasmas )
Formation and Long Term Evolution of an Externally Driven Magnetic Island in Rotating Plasmas ) Yasutomo ISHII and Andrei SMOLYAKOV 1) Japan Atomic Energy Agency, Ibaraki 3110102, Japan 1) University
More informationGA A27805 EXPANDING THE PHYSICS BASIS OF THE BASELINE Q=10 SCENRAIO TOWARD ITER CONDITIONS
GA A27805 EXPANDING THE PHYSICS BASIS OF THE BASELINE Q=10 SCENRAIO TOWARD ITER CONDITIONS by T.C. LUCE, G.L. JACKSON, T.W. PETRIE, R.I. PINSKER, W.M. SOLOMON, F. TURCO, N. COMMAUX, J.R. FERRON, A.M. GAROFALO,
More informationSTABILIZATION OF THE RESISTIVE WALL MODE IN DIII D BY PLASMA ROTATION AND MAGNETIC FEEDBACK
GA A24014 STABILIZATION OF THE RESISTIVE WALL MODE IN DIII D BY PLASMA ROTATION AND MAGNETIC FEEDBACK by M. Okabayashi, J. Bialek, M.S. Chance, M.S. Chu, E.D. Fredrickson, A.M. Garofalo, R. Hatcher, T.H.
More informationSTABILIZATION OF m=2/n=1 TEARING MODES BY ELECTRON CYCLOTRON CURRENT DRIVE IN THE DIII D TOKAMAK
GA A24738 STABILIZATION OF m=2/n=1 TEARING MODES BY ELECTRON CYCLOTRON CURRENT DRIVE IN THE DIII D TOKAMAK by T.C. LUCE, C.C. PETTY, D.A. HUMPHREYS, R.J. LA HAYE, and R. PRATER JULY 24 DISCLAIMER This
More informationW.M. Solomon 1. Presented at the 54th Annual Meeting of the APS Division of Plasma Physics Providence, RI October 29November 2, 2012
Impact of Torque and Rotation in High Fusion Performance Plasmas by W.M. Solomon 1 K.H. Burrell 2, R.J. Buttery 2, J.S.deGrassie 2, E.J. Doyle 3, A.M. Garofalo 2, G.L. Jackson 2, T.C. Luce 2, C.C. Petty
More informationMAGNETIC FIELD ERRORS: RECONCILING MEASUREMENT, MODELING AND EMPIRICAL CORRECTIONS ON DIII D
MAGNETIC FIELD ERRORS: RECONCILING MEASUREMENT, MODELING AND EMPIRICAL CORRECTIONS ON DIII D by M.J. Schaffer, T.E. Evans, J.L. Luxon, G.L. Jackson, J.A. Leuer, J.T. Scoville Paper QP1.76 Presented at
More informationExtended Lumped Parameter Model of Resistive Wall Mode and The Effective SelfInductance
Extended Lumped Parameter Model of Resistive Wall Mode and The Effective SelfInductance M.Okabayashi, M. Chance, M. Chu* and R. Hatcher A. Garofalo**, R. La Haye*, H. Remeirdes**, T. Scoville*, and T.
More informationAdvances in Global MHD Mode Stabilization Research on NSTX
1 EX/51 Advances in Global MHD Mode Stabilization Research on NSTX S.A. Sabbagh 1), J.W. Berkery 1), R.E. Bell 2), J.M. Bialek 1), S.P. Gerhardt 2), J.E. Menard 2), R. Betti 3), D.A. Gates 2), B. Hu 3),
More informationProgress Toward High Performance SteadyState Operation in DIII D
Progress Toward High Performance SteadyState Operation in DIII D by C.M. Greenfield 1 for M. Murakami, 2 A.M. Garofalo, 3 J.R. Ferron, 1 T.C. Luce, 1 M.R. Wade, 1 E.J. Doyle, 4 T.A. Casper, 5 R.J. Jayakumar,
More informationEdge Rotational Shear Requirements for the Edge Harmonic Oscillation in DIII D Quiescent H mode Plasmas
Edge Rotational Shear Requirements for the Edge Harmonic Oscillation in DIII D Quiescent H mode Plasmas by T.M. Wilks 1 with A. Garofalo 2, K.H. Burrell 2, Xi. Chen 2, P.H. Diamond 3, Z.B. Guo 3, X. Xu
More informationPlasma Stability in Tokamaks and Stellarators
Plasma Stability in Tokamaks and Stellarators Gerald A. Navratil GCEP Fusion Energy Workshop Princeton, NJ 1 May 006 ACKNOWLEDGEMENTS Borrowed VGs from many colleagues: J. Bialek, A. Garofalo,R. Goldston,
More informationELM Suppression in DIIID Hybrid Plasmas Using n=3 Resonant Magnetic Perturbations
1 EXC/P502 ELM Suppression in DIIID Hybrid Plasmas Using n=3 Resonant Magnetic Perturbations B. Hudson 1, T.E. Evans 2, T.H. Osborne 2, C.C. Petty 2, and P.B. Snyder 2 1 Oak Ridge Institute for Science
More informationCSA$9 k067s~ STUDY OF THE RESISTIVE WALL MODE IN DIIID GAMA22921 JULY 1998
STUDY OF THE RESISTIVE WALL MODE IN DIIID GAMA22921 CSA$9 k067s~ by A.M. GAROFALO, J. BIALEK, M.S. CHU, E.D. FREDRICKSON, R.J. GROEBNER, R.J. La HAYE, L.L. LAO, G.A. NAVRATIL, B.W. RICE, S.A. SABBAGH,
More informationGlobal Mode Control and Stabilization for Disruption Avoidance in Highβ NSTX Plasmas *
1 EX/P807 Global Mode Control and Stabilization for Disruption Avoidance in Highβ NSTX Plasmas * J.W. Berkery 1, S.A. Sabbagh 1, A. Balbaky 1, R.E. Bell 2, R. Betti 3, J.M. Bialek 1, A. Diallo 2, D.A.
More informationGA A25853 FAST ION REDISTRIBUTION AND IMPLICATIONS FOR THE HYBRID REGIME
GA A25853 FAST ION REDISTRIBUTION AND IMPLICATIONS FOR THE HYBRID REGIME by R. NAZIKIAN, M.E. AUSTIN, R.V. BUDNY, M.S. CHU, W.W. HEIDBRINK, M.A. MAKOWSKI, C.C. PETTY, P.A. POLITZER, W.M. SOLOMON, M.A.
More informationObservation of NeoClassical Ion Pinch in the Electric Tokamak*
1 EX/P629 Observation of NeoClassical Ion Pinch in the Electric Tokamak* R. J. Taylor, T. A. Carter, J.L. Gauvreau, P.A. Gourdain, A. Grossman, D. J. LaFonteese, D. C. Pace, L. W. Schmitz, A. E. White,
More informationComparison of Divertor Heat Flux Splitting by 3D Fields with Field Line Tracing Simulation in KSTAR
1 Comparison of Divertor Heat Flux Splitting by 3D Fields with Field Line Tracing Simulation in KSTAR W. Choe 1,2*, K. Kim 1,2, J.W. Ahn 3, H.H. Lee 4, C.S. Kang 4, J.K. Park 5, Y. In 4, J.G. Kwak 4,
More informationDIII D. by F. Turco 1. New York, January 23 rd, 2015
Modelling and Experimenting with ITER: the MHD Challenge by F. Turco 1 with J.M. Hanson 1, A.D. Turnbull 2, G.A. Navratil 1, F. Carpanese 3, C. PazSoldan 2, C.C. Petty 2, T.C. Luce 2, W.M. Solomon 4,
More informationINTERACTION OF AN EXTERNAL ROTATING MAGNETIC FIELD WITH THE PLASMA TEARING MODE SURROUNDED BY A RESISTIVE WALL
INTERACTION OF AN EXTERNAL ROTATING MAGNETIC FIELD WITH THE PLASMA TEARING MODE SURROUNDED BY A RESISTIVE WALL S.C. GUO* and M.S. CHU GENERAL ATOMICS *Permanent Address: Consorzio RFX, Padova, Italy **The
More informationExcitation of Alfvén eigenmodes with subalfvénic neutral beam ions in JET and DIIID plasmas
Excitation of Alfvén eigenmodes with subalfvénic neutral beam ions in JET and DIIID plasmas D. Borba 1,9, R. Nazikian 2, B. Alper 3, H.L. Berk 4, A. Boboc 3, R.V. Budny 2, K.H. Burrell 5, M. De Baar
More informationGA A THERMAL ION ORBIT LOSS AND RADIAL ELECTRIC FIELD IN DIIID by J.S. degrassie, J.A. BOEDO, B.A. GRIERSON, and R.J.
GA A27822 THERMAL ION ORBIT LOSS AND RADIAL ELECTRIC FIELD IN DIIID by J.S. degrassie, J.A. BOEDO, B.A. GRIERSON, and R.J. GROEBNER JUNE 2014 DISCLAIMER This report was prepared as an account of work
More informationGA A27857 IMPACT OF PLASMA RESPONSE ON RMP ELM SUPPRESSION IN DIIID
GA A27857 IMPACT OF PLASMA RESPONSE ON RMP ELM SUPPRESSION IN DIIID by A. WINGEN, N.M. FERRARO, M.W. SHAFER, E.A. UNTERBERG, T.E. EVANS, D.L. HILLIS, and P.B. SNYDER JULY 2014 DISCLAIMER This report was
More informationEffects of stellarator transform on sawtooth oscillations in CTH. Jeffrey Herfindal
Effects of stellarator transform on sawtooth oscillations in CTH Jeffrey Herfindal D.A. Ennis, J.D. Hanson, G.J. Hartwell, E.C. Howell, C.A. Johnson, S.F. Knowlton, X. Ma, D.A. Maurer, M.D. Pandya, N.A.
More informationThe EPED Pedestal Model: Extensions, Application to ELMSuppressed Regimes, and ITER Predictions
The EPED Pedestal Model: Extensions, Application to ELMSuppressed Regimes, and ITER Predictions P.B. Snyder 1, T.H. Osborne 1, M.N.A. Beurskens 2, K.H. Burrell 1, R.J. Groebner 1, J.W. Hughes 3, R. Maingi
More information(a) (b) (c) (d) (e) (f) r (minor radius) time. time. Soft Xray. T_e contours (ECE) r (minor radius) time time
Studies of Spherical Tori, Stellarators and Anisotropic Pressure with M3D 1 L.E. Sugiyama 1), W. Park 2), H.R. Strauss 3), S.R. Hudson 2), D. Stutman 4), XZ. Tang 2) 1) Massachusetts Institute of Technology,
More informationPerformance limits. Ben Dudson. 24 th February Department of Physics, University of York, Heslington, York YO10 5DD, UK
Performance limits Ben Dudson Department of Physics, University of York, Heslington, York YO10 5DD, UK 24 th February 2014 Ben Dudson Magnetic Confinement Fusion (1 of 24) Previously... In the last few
More informationThree Dimensional Effects in Tokamaks How Tokamaks Can Benefit From Stellarator Research
1 TH/P910 Three Dimensional Effects in Tokamaks How Tokamaks Can Benefit From Stellarator Research S. Günter, M. GarciaMunoz, K. Lackner, Ph. Lauber, P. Merkel, M. Sempf, E. Strumberger, D. Tekle and
More informationDIII D Research in Support of ITER
Research in Support of ITER by E.J. Strait and the Team Presented at 22nd IAEA Fusion Energy Conference Geneva, Switzerland October 1318, 28 DIIID Research Has Made Significant Contributions in the Design
More informationResponse of a Resistive and Rotating Tokamak to External Magnetic Perturbations Below the Alfven Frequency
Response of a Resistive and Rotating Tokamak to External Magnetic Perturbations Below the Alfven Freuency by M.S. Chu In collaboration with L.L. Lao, M.J. Schaffer, T.E. Evans E.J. Strait (General Atomics)
More informationA simple model of the resistive wall mode in tokamaks
A simple model of the resistive wall mode in tokamaks Richard Fitzpatrick Institute for Fusion Studies, Department of Physics, University of Texas at Austin, Austin TX 78712 (February 18, 2003) A simple
More informationEffect of nonaxisymmetric magnetic perturbations on divertor heat and particle flux profiles
1 EXD/P301 Effect of nonaxisymmetric magnetic perturbations on divertor heat and particle flux profiles JW. Ahn 1, J.M. Canik 1, R. Maingi 1, T.K. Gray 1, J.D. Lore 1, A.G. McLean 1, J.K. Park 2, A.L.
More informationLocalized Electron Cyclotron Current Drive in DIII D: Experiment and Theory
Localized Electron Cyclotron Current Drive in : Experiment and Theory by Y.R. LinLiu for C.C. Petty, T.C. Luce, R.W. Harvey,* L.L. Lao, P.A. Politzer, J. Lohr, M.A. Makowski, H.E. St John, A.D. Turnbull,
More informationRWM Control Code Maturity
RWM Control Code Maturity Yueqiang Liu EURATOM/CCFE Fusion Association Culham Science Centre Abingdon, Oxon OX14 3DB, UK Work partly funded by UK EPSRC and EURATOM. The views and opinions expressed do
More informationThe Effect of Energetic Particles on Resistive Wall Mode Stability in MAST
The Effect of Energetic Particles on Resistive Wall Mode Stability in MAST IT Chapman 1, MP Gryaznevich 1, DF Howell 1, YQ Liu 1 and the MAST Team 1 EURATOM/CCFE Fusion Association, Culham Science Centre,
More informationOverview of Tokamak Rotation and Momentum Transport Phenomenology and Motivations
Overview of Tokamak Rotation and Momentum Transport Phenomenology and Motivations Lecture by: P.H. Diamond Notes by: C.J. Lee March 19, 2014 Abstract Toroidal rotation is a key part of the design of ITER
More informationNIMROD FROM THE CUSTOMER S PERSPECTIVE MING CHU. General Atomics. Nimrod Project Review Meeting July 21 22, 1997
NIMROD FROM THE CUSTOMER S PERSPECTIVE MING CHU General Atomics Nimrod Project Review Meeting July 21 22, 1997 Work supported by the U.S. Department of Energy under Grant DEFG0395ER54309 and Contract
More informationThe Effects of Noise and Time Delay on RWM Feedback System Performance
The Effects of Noise and Time Delay on RWM Feedback System Performance O. KatsuroHopkins, J. Bialek, G. Navratil (Department of Applied Physics and Applied Mathematics, Columbia University, New York,
More informationAdvances in the Physics Basis of the Hybrid Scenario on DIIID
Advances in the Physics Basis of the Hybrid Scenario on DIIID C.C. Petty 1), W.P. West 1), J.C. DeBoo 1), E.J. Doyle 2), T.E. Evans 1), M.E. Fenstermacher 3), M. Groth 3), J.R. Ferron 1), G.R. McKee 4),
More information(Motivation) Reactor tokamaks have to run without disruptions
Abstract A database has been developed to study the evolution, the nonlinear effects on equilibria, and the disruptivity of locked and quasistationary modes with poloidal and toroidal mode numbers m=2
More informationCharacterization of neoclassical tearing modes in highperformance I mode plasmas with ICRF mode conversion flow drive on Alcator CMod
1 EX/P422 Characterization of neoclassical tearing modes in highperformance I mode plasmas with ICRF mode conversion flow drive on Alcator CMod Y. Lin, R.S. Granetz, A.E. Hubbard, M.L. Reinke, J.E.
More informationSupported by. Role of plasma edge in global stability and control*
NSTX Supported by College W&M Colorado Sch Mines Columbia U CompX General Atomics INL Johns Hopkins U LANL LLNL Lodestar MIT Nova Photonics New York U Old Dominion U ORNL PPPL PSI Princeton U Purdue U
More informationModeling of resistive wall mode and its control in experiments and ITER a
Modeling of resistive wall mode and its control in experiments and ITER a Yueqiang Liu b Department of Applied Mechanics, EURATOM/VR Fusion Association, Chalmers University of Technology, Göteborg, Sweden
More informationEffects of Noise in Time Dependent RWM Feedback Simulations
Effects of Noise in Time Dependent RWM Feedback Simulations O. KatsuroHopkins, J. Bialek, G. Navratil (Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY USA) Building
More informationResponse of a Resistive and Rotating Tokamak to External Magnetic Perturbations Below the Afvén Frequency
1 THS/P504 Response of a Resistive and Rotating Tokamak to External Magnetic Perturbations Below the Afvén Frequency M.S. Chu, 1 L.L. Lao, 1, M.J. Schaffer 1 T.E. Evans, 1 E.J. Strait, 1 Y.Q. Liu 2, M.J.
More informationInteraction of scrapeoff layer currents with magnetohydrodynamical instabilities in tokamak plasmas
Interaction of scrapeoff layer currents with magnetohydrodynamical instabilities in tokamak plasmas Richard Fitzpatrick Institute for Fusion Studies Department of Physics University of Texas at Austin
More informationControl of Sawtooth Oscillation Dynamics using Externally Applied Stellarator Transform. Jeffrey Herfindal
Control of Sawtooth Oscillation Dynamics using Externally Applied Stellarator Transform Jeffrey Herfindal D.A. Ennis, J.D. Hanson, G.J. Hartwell, S.F. Knowlton, X. Ma, D.A. Maurer, M.D. Pandya, N.A. Roberds,
More informationGA A25351 PHYSICS ADVANCES IN THE ITER HYBRID SCENARIO IN DIIID
GA A25351 PHYSICS ADVANCES IN THE ITER HYBRID SCENARIO IN DIIID by C.C. PETTY, P.A. POLITZER, R.J. JAYAKUMAR, T.C. LUCE, M.R. WADE, M.E. AUSTIN, D.P. BRENNAN, T.A. CASPER, M.S. CHU, J.C. DeBOO, E.J. DOYLE,
More informationOn tokamak plasma rotation without the neutral beam torque
On tokamak plasma rotation without the neutral beam torque Antti Salmi (VTT) With contributions from T. Tala (VTT), C. Fenzi (CEA) and O. Asunta (Aalto) 2 Motivation: Toroidal rotation Plasma rotation
More informationFirst Observation of ELM Suppression by Magnetic Perturbations in ASDEX Upgrade and Comparison to DIIID MatchedShape Plasmas
1 PD/11 First Observation of ELM Suppression by Magnetic Perturbations in ASDEX Upgrade and Comparison to DIIID MatchedShape Plasmas R. Nazikian 1, W. Suttrop 2, A. Kirk 3, M. Cavedon 2, T.E. Evans
More informationCharacterization and Forecasting of Unstable Resistive Wall Modes in NSTX and NSTXU *
1 EX/P434 Characterization and Forecasting of Unstable Resistive Wall Modes in NSTX and NSTXU * J.W. Berkery 1, S.A. Sabbagh 1, Y.S. Park 1, R.E. Bell 2, S.P. Gerhardt 2, C.E. Myers 2 1 Department of
More informationDirect drive by cyclotron heating can explain spontaneous rotation in tokamaks
Direct drive by cyclotron heating can explain spontaneous rotation in tokamaks J. W. Van Dam and L.J. Zheng Institute for Fusion Studies University of Texas at Austin 12th USEU Transport Task Force Annual
More informationRelating the LH Power Threshold Scaling to Edge Turbulence Dynamics
Relating the LH Power Threshold Scaling to Edge Turbulence Dynamics Z. Yan 1, G.R. McKee 1, J.A. Boedo 2, D.L. Rudakov 2, P.H. Diamond 2, G. Tynan 2, R.J. Fonck 1, R.J. Groebner 3, T.H. Osborne 3, and
More informationDIAGNOSTICS FOR ADVANCED TOKAMAK RESEARCH
DIAGNOSTICS FOR ADVANCED TOKAMAK RESEARCH by K.H. Burrell Presented at High Temperature Plasma Diagnostics 2 Conference Tucson, Arizona June 19 22, 2 134 /KHB/wj ROLE OF DIAGNOSTICS IN ADVANCED TOKAMAK
More informationGA A23114 DEPENDENCE OF HEAT AND PARTICLE TRANSPORT ON THE RATIO OF THE ION AND ELECTRON TEMPERATURES
GA A311 DEPENDENCE OF HEAT AND PARTICLE TRANSPORT ON THE RATIO OF THE ION AND ELECTRON TEMPERATURES by C.C. PETTY, M.R. WADE, J.E. KINSEY, R.J. GROEBNER, T.C. LUCE, and G.M. STAEBLER AUGUST 1999 This report
More informationGA A26807 RESULTS OF ITER TEST BLANKET MODULE MOCKUP EXPERIMENTS ON DIIID
GA A26807 RESULTS OF ITER TEST BLANKET MODULE MOCKUP EXPERIMENTS by J.A. SNIPES, M.J. SCHAFFER, P. GOHIL, P. de VRIES, M.E. FENSTERMACHER, T.E. EVANS, X. GAO, A.M. GAROFALO, D.A. GATES, C.M. GREENFIELD,
More informationRecent Development of LHD Experiment. O.Motojima for the LHD team National Institute for Fusion Science
Recent Development of LHD Experiment O.Motojima for the LHD team National Institute for Fusion Science 4521 1 Primary goal of LHD project 1. Transport studies in sufficiently high n E T regime relevant
More informationGA A27806 TURBULENCE BEHAVIOR AND TRANSPORT RESPONSE APPROACHING BURNING PLASMA RELEVANT PARAMETERS
GA A27806 TURBULENCE BEHAVIOR AND TRANSPORT RESPONSE APPROACHING by G.R. McKEE, C. HOLLAND, Z. YAN, E.J. DOYLE, T.C. LUCE, A. MARINONI, C.C. PETTY, T.L. RHODES, L. SCHMITZ, W.M. SOLOMON, B.J. TOBIAS, G.
More informationPREDICTIVE MODELING OF PLASMA HALO EVOLUTION IN POSTTHERMAL QUENCH DISRUPTING PLASMAS
GA A25488 PREDICTIVE MODELING OF PLASMA HALO EVOLUTION IN POSTTHERMAL QUENCH DISRUPTING PLASMAS by D.A. HUMPHREYS, D.G. WHYTE, M. BAKHTIARI, R.D. DERANIAN, E.M. HOLLMANN, A.W. HYATT, T.C. JERNIGAN, A.G.
More informationAdvanced Tokamak Research in JT60U and JT60SA
I07 Advanced Tokamak Research in and JT60SA A. Isayama for the JT60 team 18th International Toki Conference (ITC18) December 912, 2008 Ceratopia Toki, Toki Gifu JAPAN Contents Advanced tokamak development
More informationStabilization of sawteeth in tokamaks with toroidal flows
PHYSICS OF PLASMAS VOLUME 9, NUMBER 7 JULY 2002 Stabilization of sawteeth in tokamaks with toroidal flows Robert G. Kleva and Parvez N. Guzdar Institute for Plasma Research, University of Maryland, College
More informationELMs and Constraints on the HMode Pedestal:
ELMs and Constraints on the HMode Pedestal: A Model Based on PeelingBallooning Modes P.B. Snyder, 1 H.R. Wilson, 2 J.R. Ferron, 1 L.L. Lao, 1 A.W. Leonard, 1 D. Mossessian, 3 M. Murakami, 4 T.H. Osborne,
More informationMultimachine Extrapolation of Neoclassical Tearing Mode Physics to ITER
1 IT/P68 Multimachine Extrapolation of Neoclassical Tearing Mode Physics to ITER R. J. Buttery 1), S. Gerhardt ), A. Isayama 3), R. J. La Haye 4), E. J. Strait 4), D. P. Brennan 5), P. Buratti 6), D.
More informationGA A26785 GIANT SAWTEETH IN DIIID AND THE QUASIINTERCHANGE MODE
GA A26785 GIANT SAWTEETH IN DIIID AND THE QUASIINTERCHANGE MODE by A.D. TURNBULL, M. CHOI, and L.L. LAO NOVEMBER 2010 DISCLAIMER This report was prepared as an account of work sponsored by an agency
More informationCurrent Drive Experiments in the HITII Spherical Tokamak
Current Drive Experiments in the HITII Spherical Tokamak T. R. Jarboe, P. Gu, V. A. Izzo, P. E. Jewell, K. J. McCollam, B. A. Nelson, R. Raman, A. J. Redd, P. E. Sieck, and R. J. Smith, Aerospace & Energetics
More informationOn the physics of shear flows in 3D geometry
On the physics of shear flows in 3D geometry C. Hidalgo and M.A. Pedrosa Laboratorio Nacional de Fusión, EURATOMCIEMAT, Madrid, Spain Recent experiments have shown the importance of multiscale (longrange)
More informationRole of Magnetic Configuration and Heating Power in ITB Formation in JET.
Role of Magnetic Configuration and Heating Power in ITB Formation in JET. The JET Team (presented by V. Parail 1 ) JET Joint Undertaking, Abingdon, Oxfordshire, United Kingdom 1 present address: EURATOM/UKAEA
More informationDisruption dynamics in NSTX. longpulse discharges. Presented by J.E. Menard, PPPL. for the NSTX Research Team
Disruption dynamics in NSTX longpulse discharges Presented by J.E. Menard, PPPL for the NSTX Research Team Workshop on Active Control of MHD Stability: Extension of Performance Monday, November 18, 2002
More informationMeasuring from electron temperature fluctuations in the Tokamak Fusion Test Reactor
PHYSICS OF PLASMAS VOLUME 5, NUMBER FEBRUARY 1998 Measuring from electron temperature fluctuations in the Tokamak Fusion Test Reactor C. Ren, a) J. D. Callen, T. A. Gianakon, and C. C. Hegna University
More informationGA A26057 DEMONSTRATION OF ITER OPERATIONAL SCENARIOS ON DIIID
GA A26057 DEMONSTRATION OF ITER OPERATIONAL SCENARIOS ON DIIID by E.J. DOYLE, J.C. DeBOO, T.A. CASPER, J.R. FERRON, R.J. GROEBNER, C.T. HOLCOMB, A.W. HYATT, G.L. JACKSON, R.J. LA HAYE, T.C. LUCE, G.R.
More informationITR/P119 Tokamak Experiments to Study the Parametric Dependences of Momentum Transport
Tokamak Experiments to Study the Parametric Dependences of Momentum Transport T. Tala 1, R.M. McDermott 2, J.E. Rice 3, A. Salmi 1, W. Solomon 4, C. Angioni 2, C. Gao 3, C. Giroud 5, W. Guttenfelder 4,
More informationMacroscopic Stability of High β N MAST Plasmas
1 EXS/P54 Macroscopic Stability of High β N MAST Plasmas I.T. Chapman 1), R.J. Akers 1), L.C. Appel 1), N.C. Barratt 2), M.F. de Bock 1,7), A.R. Field 1), K.J. Gibson 2), M.P. Gryaznevich 1), R.J. Hastie
More informationQTYUIOP LOCAL ANALYSIS OF CONFINEMENT AND TRANSPORT IN NEUTRAL BEAM HEATED DIII D DISCHARGES WITH NEGATIVE MAGNETIC SHEAR D.P. SCHISSEL.
LOCAL ANALYSIS OF CONFINEMENT AND TRANSPORT IN NEUTRAL BEAM HEATED DIII D DISCHARGES WITH NEGATIVE MAGNETIC SHEAR Presented by D.P. SCHISSEL for the DIII D Team* Presented to 16th IAEA Fusion Conference
More informationKSTAR Equilibrium Operating Space and Projected Stabilization at High Normalized Beta
1 THS/P205 KSTAR Equilibrium Operating Space and Projected Stabilization at High Normalized Beta Y.S. Park 1), S.A. Sabbagh 1), J.W. Berkery 1), J.M. Bialek 1), Y.M. Jeon 2), S.H. Hahn 2), N. Eidietis
More informationControl of Neoclassical tearing mode (NTM) in advanced scenarios
FIRST CHENGDU THEORY FESTIVAL Control of Neoclassical tearing mode (NTM) in advanced scenarios ZhengXiong Wang Dalian University of Technology (DLUT) Dalian, China Chengdu, China, 28 Aug, 2018 Outline
More informationGA A24016 PHYSICS OF OFFAXIS ELECTRON CYCLOTRON CURRENT DRIVE
GA A6 PHYSICS OF OFFAXIS ELECTRON CYCLOTRON CURRENT DRIVE by R. PRATER, C.C. PETTY, R. HARVEY, Y.R. LINLIU, J.M. LOHR, and T.C. LUCE JULY DISCLAIMER This report was prepared as an account of work sponsored
More informationTriggering Mechanisms for Transport Barriers
Triggering Mechanisms for Transport Barriers O. Dumbrajs, J. Heikkinen 1, S. Karttunen 1, T. Kiviniemi, T. KurkiSuonio, M. Mantsinen, K. Rantamäki 1, S. Saarelma, R. Salomaa, S. Sipilä, T. Tala 1 EuratomTEKES
More informationIdentication of MultiModal Plasma Responses to Applied Magnetic Perturbations using the Plasma Reluctance
Identication of MultiModal Plasma Responses to Applied Magnetic Perturbations using the Plasma Reluctance Nikolas C. Logan 1, Carlos PazSoldan 2, JongKyu Park 1, Ra Nazikian 1 1 Princeton Plasma Physics
More informationSTATIONARY, HIGH BOOTSTRAP FRACTION PLASMAS IN DIIID WITHOUT INDUCTIVE CURRENT CONTROL
th IAEA Fusion Energy Conference Vilamoura, Portugal, to 6 November IAEACN6/EX/P7 STATIONARY, HIGH BOOTSTRAP FRACTION PLASMAS IN DIIID WITHOUT INDUCTIVE CURRENT CONTROL P.A. POLITZER, A.W. HYATT, T.C.
More informationObservation of Reduced Core Electron Temperature Fluctuations and Intermediate Wavenumber Density Fluctuations in H and QHmode Plasmas
Observation of Reduced Core Electron Temperature Fluctuations and Intermediate Wavenumber Density Fluctuations in H and QHmode Plasmas EX/P535 L. Schmitz 1), A.E. White 1), G. Wang 1), J.C. DeBoo 2),
More informationExperimental test of the neoclassical theory of poloidal rotation
Experimental test of the neoclassical theory of poloidal rotation Presented by Wayne Solomon with contributions from K.H. Burrell, R. Andre, L.R. Baylor, R. Budny, P. Gohil, R.J. Groebner, C.T. Holcomb,
More informationCharacteristics of the Hmode H and Extrapolation to ITER
Characteristics of the Hmode H Pedestal and Extrapolation to ITER The Hmode Pedestal Study Group of the International Tokamak Physics Activity presented by T.Osborne 19th IAEA Fusion Energy Conference
More informationPredicting the Rotation Profile in ITER
Predicting the Rotation Profile in ITER by C. Chrystal1 in collaboration with B. A. Grierson2, S. R. Haskey2, A. C. Sontag3, M. W. Shafer3, F. M. Poli2, and J. S. degrassie1 1General Atomics 2Princeton
More information